Characteristics of the Hf_0.5Zr_0.5O₂ Thin Films Grown by a Chemical Solution Deposition Method

Abstract

This paper describes morphological, optical, compositional, and structural characteristics of the Hf_0.5Zr_0.5O₂ (HZO) thin films grown on Si and sapphire substrates by a chemical solution deposition method by spin coating using HfCl₄ and ZrCl₄ for the starting agents. Clear and smooth HZO thin films of about 20 nm thick were obtained after the spin-coating of the chemical solution followed by a drying process at 150°C and a sintering process at 500-800°C. The compositional ratio of Hf : Zr in the HZO thin films was 1 : 1 in good agreement with the molar ratio of HfCl₄ and ZrCl₄ in the chemical solution. It was revealed that the HZO thin films were crystallized in orthorhombic structure under the sintering in N₂, while monoclinic structure became dominant under the sintering in air.